245/50R20 vs 265/40R21
265/40R21 is 8.0 mm shorter than 245/50R20 in overall diameter (−1.1%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 265/40R21 fitted, the speedometer reads 100 km/h when you are doing 98.9 km/h.
Dimensions side by side
| 245/50R20 | 265/40R21 | |
|---|---|---|
| Overall diameter | 753 mm (29.6″) | 745 mm (29.3″) |
| Section width | 245 mm | 265 mm |
| Sidewall height | 123 mm | 106 mm |
| Rim | 20″ | 21″ |
| Revolutions per km | 423 | 427 |
| In stock | 53 tires from $178.00 | 33 tires from $295.00 |
What changes
- Overall diameter: 265/40R21 is 8.0 mm shorter (−1.1%).
- Speedometer: reads 100 km/h at an actual 98.9 km/h with 265/40R21.
- 265/40R21 is 20 mm wider, so check clearance and the recommended rim width.
- Wheel size changes from 20″ to 21″: you need wheels in the new size.
- Choose a load index at least as high as the one on your door placard.
Vehicles that came with both sizes
Vehicles that use 245/50R20
Vehicles that use 265/40R21
See every alternate size for 245/50R20
Frequently asked questions
Can I use 265/40R21 instead of 245/50R20?
Usually, yes: 265/40R21 is within 3% of the overall diameter of 245/50R20 (−1.1%). Use wheels of the right size and width, match or exceed the original load index, and check clearance at full steering lock.
How much does the speedometer change between 245/50R20 and 265/40R21?
With 265/40R21 instead of 245/50R20, the speedometer shows 100 km/h when you are actually doing 98.9 km/h.
Which vehicles came with both 245/50R20 and 265/40R21?
Both sizes were original equipment, on different trims or packages, on the 2015–2024 Ford Edge, 2019–2023 Lincoln Nautilus, 2016–2018 Lincoln MKX.